Long-Term Evolution (LTE) is a 4G wireless communications standard developed by the 3rd Generation Partnership Project (3GPP) that is designed to provide increased speeds for mobile devices such as smartphones, tablets, netbooks, notebooks, wireless hotspots, etc. 4G LTE technologies are designed to provide IP-based voice, data, and multimedia streaming at high speeds.
In addition to communicating via LTE technologies, mobile devices often communicate with other mobile devices over wireless network(s). There are two spectrum bands for wireless use: a 2.4 gigahertz (GHz) spectrum band and a 5 GHz spectrum band. Most wireless devices, other than laptops, phones, and tablets, use the 2.4 GHz spectrum band. Accordingly, the 2.4 GHz spectrum band is a very crowded spectrum band. The 5 GHz spectrum band is less congested, and as such, the 5 GHz spectrum band enables networks to work at higher speeds and at greater ranges. The 5 GHz spectrum band is used by devices such as laptops, phones, and tablets. The 5 GHz spectrum band is unlicensed, meaning that any individual or organization can build a device that sends and receives signals in the 5 GHz spectrum band without obtaining permission.
LTE in unlicensed spectrum (LTE-U) uses 4G LTE technologies in unlicensed spectrum, such as the 5 GHz spectrum band described above. LTE-U enables increased coverage in cellular networks by increasing data speeds using the unlicensed 5 GHz spectrum band. That is, LTE-U enables telecommunication service providers (i.e., carriers providing cellular services) to share space with wireless equipment currently using the 5 GHz spectrum band instead of, or in addition to, the radio spectrums to which they have exclusive licenses (e.g., 4G LTE). License Assisted Access (LAA) is an LTE feature that leverages the 5 GHz spectrum band in combination with licensed spectrum to provide a performance boost for mobile device users.
LTE, LTE-U, and LAA each use different scheduling methods to ensure that multiple devices can use the 5 GHz spectrum band harmoniously (i.e., without one device appropriating the bandwidth and preventing other devices from using the 5 GHz spectrum band). For instance, LTE has various methods to mitigate interference, including Transmission Mode 9, Felcic, load-base scheduler, etc. LAA uses a method called Listen Before Talk (LBT), which is a same method that is used for wireless technologies. LTE-U uses eCSAT, which is a method used to transmit data based on previous calls.